Electronic transport through oligopeptide chains: An artificial prototype of a molecular diode

Using an effective tight-binding model, together with a transfer matrix technique, we investigate the electronic transport through an oligopeptide chain composed by two amino acid pairs alanine–lysine (Ala–Lys) and threonine–alanine (Thr–Ala), respectively, sandwiched between two platinum electrodes. Our results show that factors such as the oligopeptide chain length and the possible combinations between the amino acids residues are crucial to the diode-like profile of the current–voltage (I–V) characteristics, whose asymmetric curves were analyzed using the inverted rectification ratio (IRR).